Bearer management apparatus and method, and communication system

ABSTRACT

A terminal is capable dual connectivity with a base station, the terminal including: a processor configured to perform a process that change, release, or deactivate a bearer among Secondary Cell Group, and to trigger transmission of a Packet Data Convergence Protocol (PDCP) status report according to the process; and, a transmitter configured to transmit the PDCP status report.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 15/272,868, which was filed on Sep. 22, 2016 and is a continuationapplication of International Application PCT/CN2014/074270 filed on Mar.28, 2014, the entire contents of each are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to a technical field of communications,and particularly, to a bearer management apparatus and method, and acommunication system.

BACKGROUND

In a heterogeneous network deployed with small cells, the dualconnectivity (DC) technology can be used to increase the throughput of aUser Equipment (UE), enhance the mobility robustness, decrease thenetwork signaling overhead, etc.

FIG. 1 is a schematic diagram of making dual connectivity in therelevant art. As illustrated in FIG. 1, a base station (such as an eNB)can configure dual connectivity for a UE in a connected status andhaving a multi-transceiving function with. When dual connectivity isconfigured, schedulers on two different eNBs (eNodeBs) are employed toprovide radio resources to the UE for data transmission, and the twoeNBs are usually connected to each other through a non-ideal backhaul X2interface.

In which, an eNB retaining an S1-MME interface with a MobilityManagement Entity (MME) is referred to as Master eNB (MeNB), and servicecells associated with the MeNB constitute a Master Cell Group (MCG); theother eNB, which is only used to provide additional radio resources, isreferred to as Secondary eNB (SeNB), and correspondingly, service cellsassociated with the SeNB constitute a Secondary Cell Group (SCG).

In the Evolved Universal Terrestrial Radio Access Network (E-UTRAN), abearer refers to a data transmission channel and a configurationthereof, and different bearers may have different configurations totransmit services required by different Qualities of Service (QoS). Thebearer on the radio interface is referred to as Radio Bearer (RB), forexample a user plane bearer is referred to as Data Radio Bearer (DRB),and a control plane bearer is referred to as Signaling Radio Bearer(SRB). When dual connectivity is configured, the RBs can be classifiedinto three types: MCG bearer, SCG bearer and split bearer.

FIG. 2 is a schematic diagram of a radio protocol stack corresponding toa bearer under dual connectivity. As illustrated in FIG. 2, in theperspective of protocol stack, the MCG bearer refers to a bearer whichperforms corresponding data transmission only using MeNB resources andto which a radio protocol stack corresponding is only located on theMeNB, the SCG bearer refers to a bearer which performs correspondingdata transmission only using SeNB resources and to which a radioprotocol stack corresponding is only located on the SeNB, and the splitbearer refers to a bearer which uses both MeNB resources and SeNBresources and to which a radio protocol stack corresponding is on bothof the MeNB and the SeNB.

As to the UE configured with dual connectivity, the network side candetermine the type of the bearer for which the service of the UE isconfigured according to the network load and the service attribute ofthe UE, i.e., whether the service of the UE is configured to betransmitted on the MCG bearer, or the SCG bearer, or the split bearer.

On the other hand, in the relevant art, the network supports theaddition, modification and release of the DRB through a procedure(RRCConnectionReconfiguration) of radio resource management connectionreconfiguration. The configuration (including reconfiguration) of theDRB and the configuration limitation are described as follows:

-   -   Evolved Packet System (EPS) bearer identity        (eps-BearerIdentity). This parameter is only configured when the        DRB is established, and cannot be configured under other        condition.    -   DRB identity (drb-Identity). This parameter remains unchanged        during the presence of the DRB.    -   Packet Data Convergence Protocol (PDCP) configuration        (pdcp-Config). This parameter must be configured when the DRB is        established, selectively configured in a case of handover and        RRC reestablishment, and cannot be configured under other        condition.    -   Radio Link Control (RLC) configuration (rlc-Config). This        parameter must be configured when a DRB is established, and        selectively configured under other condition.    -   Logical channel identity (logicalChannelIdentity). This        parameter is only configured when the DRB is established, and        cannot be configured under other condition.    -   Logical channel configuration (logicalChannelConfig). This        parameter must be configured when the DRB is established, and        selectively configured under other condition.

Generally, the network side takes the DRB identity as an anchor for theDRB management, including the establishment, modification and release ofthe RB. In a case where the service site of the UE is changed (e.g.,handed over), if the target site and the source site have differentversions, it is possible that the target site cannot parse theconfiguration of the eNB by the source site. At that time, the targetsite will adopt a full configuration, and the network side takes the EPSbearer identity as an anchor for the RB management, including theestablishment and release of the RB.

In addition, when dual connectivity is configured, the MeNB and the SeNBindependently maintain the configuration of the logical channel,including independently configuring the logical channel identity. Thatis, the MeNB and the SeNB can configure different RBs of the UE with thesame or different logical channel identities.

For example, in FIG. 2, the logical channel identities corresponding tobearer 1 and bearer 3 are independently configured by the MeNB and theSeNB, respectively, and they may be the same as or different from eachother. Similarly, the DRB identity under the scene of dual connectivitymay also be independently configured by the MeNB and the SeNB, i.e., theMeNB and the SeNB can configure different RBs of the UE with the same ordifferent DRB identities.

It shall be noted that the above description of the background is merelyprovided for clear and complete explanation of the present disclosureand for easy understanding by those skilled in the art. And it shall notbe understood that the above technical solution is known to thoseskilled in the art as it is described in the background of the presentdisclosure.

SUMMARY

However, the inventor finds that in the relevant art, a conversion fromthe SCG bearer to the MCG bearer, or from the split bearer to the MCGbearer, etc. will occur under some scenes, which causes a data dropoutthat leads to a service interruption, and currently a seamless bearerconversion cannot be carried out.

The embodiments of the present disclosure provide a bearer managementapparatus and method, and a communication system, so as to carry out aseamless bear conversion for a user equipment of dual connectivity.

According to a first aspect of the embodiments of the presentdisclosure, there is provided a bearer management method applied to auser equipment (UE) configured with dual connectivity, including:

receiving an indication message, sent by a base station, for changing abearer type of a bearer or releasing the bearer under dual connectivity;and

changing the bearer type of the bearer or releasing the bearer accordingto the indication message.

According to a second aspect of the embodiments of the presentdisclosure, there is provided a bearer management apparatus configuredin a user equipment (UE) configured with dual connectivity, including:

a message receiving unit, configured to receive an indication message,sent by a base station, for changing a bearer type of a bearer orreleasing the bearer under dual connectivity; and

a configuring unit, configured to change the bearer type of the beareror release the bearer according to the indication message.

According to a third aspect of the embodiments of the presentdisclosure, there is provided a bearer management method applied to auser equipment (UE) configured with dual connectivity, including:

releasing a Secondary Cell Group (SCG) portion corresponding to a splitbearer; or, releasing corresponding SCG when all bearers associated withan SCG are released.

According to a fourth aspect of the embodiments of the presentdisclosure, there is provided a bearer management apparatus configuredin a user equipment (UE) configured with dual connectivity, including:

a first processing unit, configured to release a Secondary Cell Group(SCG) portion corresponding to a split bearer; or, release or deactivatecorresponding SCG when all bearers associated with an SCG are released.

According to a fifth aspect of the embodiments of the presentdisclosure, there is provided a bearer management method applied to afirst base station connected to a user equipment (UE) configured withdual connectivity, including:

detecting that a radio connection fails at the UE configured with dualconnectivity; and

sending to a second base station a request for releasing an associatedSecondary Cell Group (SCG) bearer or a split bearer, so that the secondbase station releases a corresponding bearer.

According to a sixth aspect of the embodiments of the presentdisclosure, there is provided a bearer management apparatus configuredin a first base station connected to a user equipment (UE) configuredwith dual connectivity, including:

a detecting unit, configured to detect that a radio connection fails atthe UE configured with dual connectivity; and

a sending unit, configured to send to a second base station a requestfor releasing an associated Secondary Cell Group (SCG) bearer or a splitbearer, so that the second base station releases a corresponding bearer.

According to a seventh aspect of the embodiments of the presentdisclosure, there is provided a bearer management method applied to asecond base station connected to a user equipment (UE) configured withdual connectivity, including:

receiving a request, sent by a first base station, for releasing anassociated Secondary Cell Group (SCG) bearer or a split bearer; and

releasing a corresponding bearer according to the request for releasing.

According to an eighth aspect of the embodiments of the presentdisclosure, there is provided a bearer management apparatus configuredin a second base station connected to a user equipment (UE) configuredwith dual connectivity, including:

a receiving unit, configured to receive a request, sent by a first basestation, for releasing an associated Secondary Cell Group (SCG) beareror a split bearer; and

a releasing unit, configured to release a corresponding bearer accordingto the request for releasing.

According to a ninth aspect of the embodiments of the presentdisclosure, there is provided a communication system, including:

a user equipment (UE) configured with dual connectivity, configured toreceive an indication message, sent by a base station, for changing abearer type of a bearer or releasing the bearer under dual connectivity;change the bearer type of the bearer or release the bearer according tothe indication message; and send a response message to the base station;

or, configured to release a Secondary Cell Group (SCG) portioncorresponding to a split bearer after a Radio Resource Control (RRC)connection reestablishment procedure is triggered;

or, configured to release corresponding SCG resource when all bearersassociated with an SCG are released.

According to a tenth aspect of the embodiments of the presentdisclosure, there is provided a communication system, including:

a first base station, configured to detect that a radio connection failsat a user equipment (UE) configured with dual connectivity; and send toa second base station a request for releasing an associated SecondaryCell Group (SCG) bearer or a split bearer; and

a second base station, configured to receive the request, sent by thefirst base station, for releasing the associated SCG bearer or the splitbearer; and release a corresponding bearer according to the request forreleasing.

According to another aspect of the embodiments of the presentdisclosure, there is provided a computer readable program, when beingexecuted in a user equipment (UE), the program enables a computer toperform, in the UE, the aforementioned bearer management method.

According to still another aspect of the embodiments of the presentdisclosure, there is provided a storage medium which stores a computerreadable program, the computer readable program enables a computer toperform, in a user equipment (UE), the aforementioned bearer managementmethod.

According to still another aspect of the embodiments of the presentdisclosure, there is provided a computer readable program, when beingexecuted in a base station, the program enables a computer to perform,in the base station, the aforementioned bearer management method.

According to still another aspect of the embodiments of the presentdisclosure, there is provided a storage medium which stores a computerreadable program, wherein the computer readable program enables acomputer to perform, in a base station, the aforementioned bearermanagement method.

The embodiments of the present disclosure have the following beneficialeffect: by receiving an indication message, sent by a base station, forchanging a bearer type of a bearer or releasing the bearer under dualconnectivity, a UE configured with dual connectivity can carry out aseamless bearer conversion.

With reference to the following description and drawings, the particularembodiments of the present disclosure are disclosed in details, and theprinciples of the present disclosure and the manners of use areindicated. It shall be understood that the scope of the embodiments ofthe present disclosure is not limited thereto. The embodiments of thepresent disclosure contain many alternations, amendments and equivalentswithin the scope of the terms of the appended claims.

Features that are described and/or illustrated with respect to oneembodiment may be used in the same way or in a similar way in one ormore other embodiments and/or in combination with or instead of thefeatures of the other embodiments.

It shall be emphasized that the term “comprise/include” used in thisspecification is taken to specify the presence of stated features,integers, steps or components but does not preclude the presence oraddition of one or more other features, integers, steps, components orgroups thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

Many aspects of the present disclosure can be better understood withreference to the following drawings. The components in the drawings arenot necessarily to scale, emphasis instead being placed upon clearlyillustrating the principles of the present disclosure. To facilitateillustrating and describing some parts of the present disclosure,corresponding portions of the drawings may be exaggerated or reduced.

Elements and features depicted in one drawing or embodiment of thepresent disclosure may be combined with elements and features depictedin one or more additional drawings or embodiments. Moreover, in thedrawings, like reference numerals designate corresponding componentsthroughout the several views and may be used to designate correspondingcomponents in more than one embodiment.

FIG. 1 is a schematic diagram of making dual connectivity in therelevant art;

FIG. 2 is a schematic diagram of a radio protocol stack corresponding toa bearer under dual connectivity;

FIG. 3 is a schematic diagram of UE movement in a heterogeneous networkof an embodiment of the present disclosure;

FIG. 4 is a schematic diagram of a flow of a bearer management method ofEmbodiment 1 of the present disclosure;

FIG. 5 is a schematic diagram of another flow of a bearer managementmethod of Embodiment 1 of the present disclosure;

FIG. 6 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 1 of the present disclosure;

FIG. 7 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 1 of the present disclosure;

FIG. 8 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 1 of the present disclosure;

FIG. 9 is a schematic diagram of a flow of a bearer management method ofEmbodiment 2 of the present disclosure;

FIG. 10 is a schematic diagram of another flow of a bearer managementmethod of Embodiment 2 of the present disclosure;

FIG. 11 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 2 of the present disclosure;

FIG. 12 is a schematic diagram of a flow of a bearer management methodof Embodiment 3 of the present disclosure;

FIG. 13 is a schematic diagram of a structure of a bearer managementapparatus of Embodiment 4 of the present disclosure;

FIG. 14 is a schematic block diagram of a system structure of UE ofEmbodiment 4 of the present disclosure;

FIG. 15 is a schematic diagram of a structure of a bearer managementapparatus of Embodiment 5 of the present disclosure;

FIG. 16 is a schematic diagram of a structure of a bearer managementapparatus of Embodiment 6 of the present disclosure;

FIG. 17 is a schematic diagram of another structure of a bearermanagement apparatus of Embodiment 6 of the present disclosure;

FIG. 18 is a schematic diagram of a structure of a base station ofEmbodiment 6 of the present disclosure; and

FIG. 19 is a schematic diagram of a structure of a communication systemof Embodiment 7 of the present disclosure.

DESCRIPTION OF THE EMBODIMENTS

The above and other features of the present disclosure will be apparentwith reference to the following description and drawings. In thedescription and drawings, particular embodiments of the disclosure aredisclosed in details as being indicative of some of the ways in whichthe principles of the present disclosure may be employed, but it shallbe understood that the present disclosure is not limited to thoseembodiments described. Rather more, the present disclosure includes allchanges, modifications and equivalents falling within the scope of theappended claims.

Under the scene of dual connectivity, the network side may determinewhether to bear the service on an MCG bearer, an SCG bearer or a splitbearer according to the network load, the service attribute, and the UElocation. FIG. 3 is a schematic diagram of UE movement in aheterogeneous network of an embodiment of the present disclosure. Asillustrated in FIG. 3, a moving path of the UE is indicated with adotted line. When the UE moves to point A, the network side may transferone or more bearers of the UE onto the SeNB, which causes a conversionfrom the MCG bearer to the SCG bearer, or from the MCG bearer to thesplit bearer. When the UE moves to point C, the network side maytransfer the one or more bearers of the UE on the SeNB back to the MeNB,which causes a conversion from the SCG bearer to the MCG bearer, or fromthe split bearer to the MCG bearer.

In the case of a conversion between the bearers, such as from the SCGbearer to the MCG bearer, one way is to release the SCG bearer, and thenestablish an MCG bearer on the MCG to recover the bearer. This way has adisadvantage that releasing the bearer at first will release thePDCP/RLC entity associated with the bearer, thereby causing a datadropout that leads to a service interruption. In order to avoid the datadropout, a seamless conversion shall be performed for the bearer, i.e.,the source SCG bearer is converted to the MCG bearer through areconfiguration. How to perform such a seamless conversion is a problemto be solved by the present application.

Specifically, the embodiments of the present disclosure mainly solve thefollowing three problems.

Firstly, as described above, the MeNB and the SeNB independentlyconfigure logical channel identities corresponding to the bearers. Forexample in FIG. 2, logical channel identities configured for MCG bearer1 and SCG bearer 1 by the MeNB and the SeNB respectively are bothLCID=1. In that case, if SCG bearer 1 is seamlessly converted to the MCGbearer, the existing mechanism cannot support the modification of thelogical channel identity, and there will be a situation that logicalchannel identities corresponding to the two bearers on the UE are bothLCID=1. Thus, when a Medium Access Control (MAC) entitymultiplexing/de-multiplexing is performed, the error of themultiplexing/de-multiplexing will be occurred, because the network sideand the UE cannot recognize the RB to which the data of the bearers onthe logical channels belongs as the logical channels are the same.

Secondly, assuming that the RB identities are independently configuredby the MeNB and the SeNB, for example in FIG. 2, the RB identitiesconfigured for MCG bearer 1 and SCG bearer 1 by the MeNB and the SeNBrespectively are both DRB=1. In that case, if SCG bearer 1 is seamlesslyconverted to the MCG bearer, the existing mechanism will take the DRBidentity as the anchor when performing a DRB reconfiguration, thus a DRBidentity reconfiguration is not supported in that case. As a result, twoMCG bearers having the same DRB identity DRB=1 will occur to cause aconfusion of DRB identities, and the UE and the network side cannotrecognize the two bearers.

Thirdly, if the SCG bearer is converted to the MCG bearer, the MeNB mayneed to reconfigure the PDCP entity corresponding to the MCG bearer,such as modifying the header compression algorithm, because differentconfigurations of the bearer may be performed by different service sitesin consideration of the change of the service site of the bearer. Inthat case, such a function cannot be supported by the existingmechanism.

Regarding the above problems, the embodiments of the present disclosurewill be described in details as follows.

Embodiment 1

This embodiment of the present disclosure provides a bearer managementmethod applied to a UE configured with dual connectivity. FIG. 4 is aschematic diagram of a flow of a bearer management method of Embodiment1 of the present disclosure. As illustrated in FIG. 4, the methodincludes:

step 401: the UE receives an indication message, sent by a base station,for changing a bearer type of a bearer or releasing the bearer underdual connectivity; and

step 402: the UE changes the bearer type of the bearer or releases thebearer according to the indication message.

As illustrated in FIG. 4, the method may further include:

step 403: the UE sends a response message to the base station.

In this embodiment, the change of the bearer type may include a changefrom MCG bearer to SCG bearer, a change from SCG bearer to MCG bearer, achange from MCG bearer to split bearer, and a change from SCG 1 bearerto SCG 2 bearer (a change of SCG bearers in different SCGs). But thepresent disclosure is not limited thereto, and the specific scene can bedetermined according to the actual conditions.

In this embodiment, the base station may be one of those making dualconnectivity with the UE, such as an MeNB or an SeNB, but the presentdisclosure is not limited thereto, and the specific base station may bedetermined according to the actual conditions.

In one embodiment, the indication message includes first configurationinformation configured or reconfigured by the base station for a logicalchannel identity corresponding to the bearer; and the method furtherincludes: configuring or reconfiguring the logical channel identitycorresponding to the bearer according to the first configurationinformation.

FIG. 5 is a schematic diagram of another flow of a bearer managementmethod of Embodiment 1 of the present disclosure. As illustrated in FIG.5, the method includes:

step 501: a base station sends a Radio Resource Control (RRC) messagefor changing a bearer type under dual connectivity, and reconfiguring abearer of a changed bearer type, the RRC message containing firstconfiguration information that includes information of (re)configurationof a logical channel identity corresponding to the bearer by the basestation;

step 502: UE receives the RRC message of step 501, converts the bearertype according to a configuration, and (re)configures the logicalchannel identity corresponding to the bearer according to the firstconfiguration information;

step 503: the UE returns an RRC response message.

In this embodiment, the first configuration information may includelogical ChannelIdentity in an information element DRB-ToAddMod. In theperspective of the existing protocol, the method is described asfollows:

DRB-ToAddMod ::= SEQUENCE {  eps-BearerIdentity  INTEGER (0 . . . 15)OPTIONAL, -- Cond DRB-Setup  drb-Identity DRB-Identity,  pdcp-Config PDCP-Config OPTIONAL, -- Cond PDCP  rlc-Config  RLC-Config OPTIONAL, --Cond Setup  logicalChannelIdentity  INTEGER (3 . . . 10) OPTIONAL, --Cond LCID  logicalChannelConfig LogicalChannelConfig OPTIONAL, -- CondSetup  . . . }

The presence condition LCID of the logicalChannelIdentity indicates: theinformation element must be present when an associated DRB isestablished, is selectively present (i.e., either present ornon-present) when a bearer type under dual connectivity is changed, andis not allowed to be present under other condition.

In another embodiment, the indication message includes secondconfiguration information for the base station to configure orreconfigure a radio bearer identity corresponding to the bearer; and themethod further includes: configuring or reconfiguring a radio beareridentity corresponding to the bearer according to the secondconfiguration information.

FIG. 6 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 1 of the present disclosure. Asillustrated in FIG. 6, the method includes:

step 601: a base station sends an RRC message for changing a bearer typeunder dual connectivity, and reconfiguring a bearer of a changed bearertype, the RRC message containing second configuration information thatincludes information of (re)configuration of an RB identitycorresponding to the bearer by the base station;

step 602: the UE receives the RRC message of step 601, changes thebearer type according to a configuration, and (re)configures an RBidentity corresponding to the bearer and reconfigures the beareraccording to the second configuration information by using an EPS beareridentity as an anchor;

step 603: the UE returns an RRC response message.

In this embodiment, the second configuration information containseps-BearIdentity in an information element DRB-ToAddMod. In theperspective of the existing protocol, the method is described asfollows:

If an EPS bearer identity included in a DRB addition/modification list(DRB-ToAddModList) is in a current configuration of the UE and thebearer is changing the bearer type, then the UE

-   -   applies a DRB identity to the bearer when the configuration        information contains the DRB identity;    -   applies a PDCP configuration when the configuration information        contains the PDCP configuration;    -   applies an RLC configuration when the configuration information        contains the RLC configuration;    -   applies a logical channel identity configuration when the        configuration information contains the logical channel identity        configuration; and    -   applies a logical channel configuration when the configuration        information contains the logical channel configuration.

DRB-ToAddMod ::= SEQUENCE {  eps-BearerIdentity  INTEGER (0 . . . 15)OPTIONAL, -- Cond EPS-bearer-ID  drb-Identity  DRB-Identity, pdcp-Config  PDCP-Config OPTIONAL, -- Cond PDCP  rlc-Config  RLC-ConfigOPTIONAL, -- Cond Setup  logicalChannelIdentity  INTEGER (3 . . . 10)OPTIONAL, -- Cond DRB-Setup  logicalChannelConfig LogicalChannelConfigOPTIONAL, -- Cond Setup  . . . }

The presence condition EPS-bearer-ID of the eps-BearerIdentityindicates: the information element must be present when an associatedDRB is established, is selectively present (i.e., either present ornon-present) when a bearer type under dual connectivity is changed, andis not allowed to be present under other condition.

In another embodiment, the indication message includes thirdconfiguration information for the base station to configure orreconfigure a PDCP identity corresponding to the bearer; and the methodfurther includes: configuring or reconfiguring a PDCP entitycorresponding to the bearer according to the third configurationinformation.

FIG. 7 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 1 of the present disclosure. Asillustrated in FIG. 7, the method includes:

step 701: a base station sends an RRC message for changing a bearer typeunder dual connectivity, and reconfiguring a bearer of a changed bearertype, the RRC message containing third configuration information thatincludes information (re)configuration of a PDCP entity corresponding tothe bearer by the base station;

step 702: the UE receives the RRC message of step 701, changes thebearer type according to a configuration, and (re)configures a PDCPentity corresponding to the bearer according to the third configurationinformation; and

step 703: the UE returns an RRC response message.

In this embodiment, the third configuration information containspdcp-Config in an information element DRB-ToAddMod. In the perspectiveof the existing protocol, the method is described as follows:

DRB-ToAddMod ::= SEQUENCE {  eps-BearerIdentity  INTEGER (0 . . . 15)OPTIONAL, -- Cond DRB-Setup  drb-Identity DRB-Identity,  pdcp-Config PDCP-Config OPTIONAL, -- Cond PDCP2  rlc-Config  RLC-Config OPTIONAL,-- Cond Setup  logicalChannelIdentity  INTEGER (3 . . . 10) OPTIONAL, --Cond DRB-Setup  logicalChannelConfig LogicalChannelConfig OPTIONAL, --Cond Setup  . . . }

The presence condition PDCP2 of the pdcp-config indicates: theinformation element must be present when an associated DRB isestablished, is selectively present (i.e., either present ornon-present) when a completely configured intra-E-UTRA handover is notused, when a first RRC connection reconfiguration after an RRCconnection reestablishment, or when the bearer type changes for UE(s)configured with dual connectivity, and is not allowed to be presentunder other condition.

In another embodiment, the indication message includes fourthconfiguration information for releasing the bearer under dualconnectivity.

FIG. 8 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 1 of the present disclosure. Asillustrated in FIG. 8, the method includes:

step 801: a base station sends an RRC message for releasing a bearerunder dual connectivity, the RRC message containing fourth configurationinformation that includes release information of the bearer under dualconnectivity;

step 802: UE receives the RRC message of step 801, and releases thebearer according to a configuration; and

step 803: the UE returns an RRC response message.

In this embodiment, step 802 releases a data radio bearer correspondingto an EPS bearer identity according to the fourth configurationinformation, when the EPS bearer identity is not contained in theinformation element DRB-ToAddMod while belonging to a currentconfiguration of the UE configured with dual connectivity; or step 802releases a data radio bearer corresponding to an EPS bearer identityaccording to the fourth configuration information, when the EPS beareridentity is not contained in the information element DRB-ToAddMod whilebelonging to a current configuration of the UE and the indicationmessage is a first RRC connection reconfiguration message after an RRCconnection reestablishment, and the UE is configured with dualconnectivity.

Specifically, if the EPS bearer identity is not included in a DRBaddition/modification list (DRB-ToAddModList) while belonging to acurrent configuration of the UE configured with dual connectivity, orthe message is a first RRC connection reconfiguration message after anRRC connection reestablishment, and the UE is configured with dualconnectivity, then the UE releases a DRB corresponding to the EPS beareridentity.

As can be seen from the above embodiment, by receiving an indicationmessage, sent by a base station, for changing a bearer type of a beareror releasing the bearer under dual connectivity, the UE configured withdual connectivity can seamlessly convert the bearer.

Embodiment 2

This embodiment of the present disclosure provides a bearer managementmethod applied to a UE configured with dual connectivity. FIG. 9 is aschematic diagram of a flow of a bearer management method of Embodiment2 of the present disclosure. As illustrated in FIG. 9, the methodincludes:

Step 901: the UE releases a Secondary Cell Group (SCG) portioncorresponding to a split bearer; or, releases corresponding SCG resourcewhen all bearers associated with an SCG are released.

In one embodiment, the UE may release the SCG portion corresponding tothe split bearer after triggering the RRC connection reestablishmentprocedure.

FIG. 10 is a schematic diagram of another flow of a bearer managementmethod of Embodiment 2 of the present disclosure. As illustrated in FIG.10, the method includes:

step 1001: the UE triggers an RRC connection reestablishment procedure;and

step 1002: after triggering the RRC connection reestablishmentprocedure, the UE releases an RB which is an SCG portion correspondingto the split bearer and/or an SCG bearer.

In this embodiment, performing an RRC connection reestablishmentprocedure for the UE configured with dual connectivity includes: aftertriggering the RRC connection reestablishment procedure, the UE returnsto the traditional single connection mode (i.e., only being connected tothe MeNB), which includes releasing configurations associated with theSCG such as a UE identity under the SCG an MAC/PHY configurationcorresponding to the SCG an SCG measurement configuration, etc.

FIG. 11 is a schematic diagram of still another flow of a bearermanagement method of Embodiment 2 of the present disclosure. Asillustrated in FIG. 11, the method includes:

step 1101: the UE triggers an RRC connection reestablishment procedure;and

step 1102: after triggering the RRC connection reestablishmentprocedure, the UE returns to the traditional single connection mode(i.e., only being connected to the MeNB), including: releasing an SCGportion corresponding to the split bearer, associating all the SCGbearers to the MeNB, i.e., associating those SCG bearers to an MACentity corresponding to the MeNB, and releasing configurationsassociated with the SCG. The configurations associated with the SCG forexample include a UE identity under the SCG an MAC/PHY configurationcorresponding to the SCG an SCG measurement configuration, etc.

In another embodiment, when all bearers associated with one SCG arereleased, the UE voluntarily releases corresponding SCG, releasing theSCG may include releasing the SCG configuration and releasing the SCGresource, etc., but the present disclosure is not limited thereto.

In another embodiment, when all bearers associated with the SCG arereleased, corresponding SCG may be deactivated. In addition, thecorresponding SCG may not include cells of the SCG configured with aPUCCH and having a part of the function of primary cell.

Specifically, when all bearers associated with one SCG are released, theUE voluntarily deactivates corresponding SCG including voluntarilydeactivating all Secondary cells (Scells) associated with thecorresponding SCG excluding special Scells. The special SCell refers toan SCG cell configured with a PUCCH and having a part of the function ofthe Primary cell (Pcell).

In another embodiment, when a bearer change from the split bearer to thetraditional bearer, or from the split bearer to the MCG bearer occurs, aPDCP entity may be reestablished and/or a sending of a PDCP statusreport to the MCG may be triggered. In addition, a PDCP datatransmission or retransmission may be performed according to thereceived PDCP status report sent from the network side.

Specifically, when a bearer change from the split bearer to thetraditional bearer, or from the split bearer to the MCG bearer occurs,the UE reestablishes a PDCP entity, and/or the UE triggers a sending ofa PDCP status report to the MeNB. In addition, the UE may furtherperform a PDCP data transmission or retransmission according to thereceived PDCP status report sent from the network side, i.e., perform atransmission or retransmission of PDCP packet indicated by the PDCPstatus report as still not being acknowledged by the network side.

As can be seen from the above embodiment, by receiving an indicationmessage, sent by a base station, for changing a bearer type of a beareror releasing the bearer under dual connectivity, the UE configured withdual connectivity can seamlessly convert the bearer.

Embodiment 3

This embodiment of the present disclosure provides a bearer managementmethod applied to a base station connected to a UE configured with dualconnectivity.

FIG. 12 is a schematic diagram of a flow of a bearer management methodof Embodiment 3 of the present disclosure. As illustrated in FIG. 12,the method includes:

step 1201: a first base station detects that a radio connection fails ata UE configured with dual connectivity;

step 1202: the first base station sends to a second base station arequest for releasing an associated SCG bearer or a split bearer.

As illustrated in FIG. 12, the method further includes:

step 1203: the second base station receives the request, sent by thefirst base station, for releasing the associated SCG bearer or the splitbearer; and

step 1204: the second base station releases a corresponding beareraccording to the request for releasing.

For example, when detecting that a radio connection fails at the UEconfigured with dual connectivity, e.g., receiving an RRC connectionreestablishment request message or judging a Radio Link Failure (RLF) atthe UE, the MeNB sends a request for releasing the associated SCG beareror the split bearer to the SeNB, the request containing a release reasonof User inactivity or Radio Connection With UE Lost. The SeNB releasescorresponding bearer.

For another example, when detecting an RLF at the UE configured withdual connectivity, the SeNB sends a request for releasing the associatedSCG bearer or the split bearer to the MeNB, the request containing arelease reason of User inactivity or Radio Connection With UE Lost. TheMeNB returns a response message.

As can be seen from the above embodiment, by releasing the SCG bearer orthe split bearer at the base station side, the UE configured with dualconnectivity can seamlessly convert the bearer.

Embodiment 4

This embodiment of the present disclosure provides a bearer managementapparatus configured in a UE configured with dual connectivity. Thisembodiment of the present disclosure is corresponding to a bearermanagement method of Embodiment 1, and the same contents are omitted.

FIG. 13 is a schematic diagram of a structure of a bearer managementapparatus of Embodiment 4 of the present disclosure. As illustrated inFIG. 13, a bearer management apparatus 1300 includes a message receivingunit 1301 and a configuring unit 1302.

In which, the message receiving unit 1301 is configured to receive anindication message, sent by a base station, for changing a bearer typeof a bearer or releasing the bearer under dual connectivity; and theconfiguring unit 1302 is configured to change the bearer type of thebearer or releases the bearer according to the indication message.

As illustrated in FIG. 13, the bearer management apparatus 1300 mayfurther include a message responding unit 1303 that is configured tosend a response message to the base station.

In this embodiment, the indication message may include firstconfiguration information configured or reconfigured by the base stationfor a logical channel identity corresponding to the bearer, or secondconfiguration information configured or reconfigured by the base stationfor a radio bearer identity corresponding to the bearer, or thirdconfiguration information configured or reconfigured by the base stationfor a PDCP entity corresponding to the bearer, or fourth configurationinformation for releasing the bearer under dual connectivity.

In which, the configuring unit 1302 may further be configured toconfigure or reconfigure the logical channel identity corresponding tothe bearer according to the first configuration information, orconfigure or reconfigure the radio bearer identity corresponding to thebearer according to the second configuration information, or configureor reconfigure the PDCP entity corresponding to the bearer according tothe third configuration information.

The configuring unit 1302 may further be configured to release a DRBcorresponding to an EPS bearer identity according to the fourthconfiguration information, when the EPS bearer identity is not containedin an information element DRB-ToAddMod while belonging to the currentconfiguration of a UE configured with dual connectivity; or, release theDRB corresponding to the EPS bearer identity according to the fourthconfiguration information, when the EPS bearer identity is not containedin the information element DRB-ToAddMod while belonging to the currentconfiguration of the UE, and the indication message including the fourthconfiguration information is a first RRC connection reconfigurationmessage after an RRC connection reestablishment, and the UE isconfigured with dual connectivity.

In this embodiment, the first configuration information contains alogicalChannelIdentity in an information element DRB-ToAddMod, and alogical channel identity corresponding to the logicalChannelIdentity ispresent when the associated DRB is established; or, the secondconfiguration information contains an eps-BearIdentity in theinformation element DRB-ToAddMod, and an EPS bearer identitycorresponding to the eps-BearIdentity is present when the associated DRBis established; or, the third configuration information includes apdcp-Config in the information element DRB-ToAddMod, and PDCPinformation corresponding to the pdcp-Config is present when theassociated DRB is established.

In which, a logical channel identity corresponding to thelogicalChannelIdentity may also be present when the bearer type changesfor UE(s) configured with dual connectivity; or an EPS bearer identitycorresponding to the eps-BearIdentity may also be present when thebearer type changes for UE(s) configured with dual connectivity; or PDCPinformation corresponding to the pdcp-Config may also be present when acompletely configured intra-E-UTRA handover is not used, or during afirst RRC connection reconfiguration after an RRC connectionreestablishment, or the bearer type changes for UE(s) configured withdual connectivity.

This embodiment of the present disclosure further provides a UEincluding the aforementioned bearer management apparatus 1300.

FIG. 14 is a schematic block diagram of a system structure of UE 1400 ofEmbodiment 4 of the present disclosure. As illustrated in FIG. 14, theUE 1400 may include a Central Processing Unit (CPU) 100 and a memory 140coupled to the CPU 100. To be noted, the drawing is illustrative, andother type of structure may also be used to supplement or replace thestructure, so as to realize the telecom function or other function.

In one embodiment, the functions of the bearer management apparatus 1300may be integrated into the CPU 100, the CPU 100 may be configured toimplement the bearer management method of Embodiment 1.

In another embodiment, the bearer management apparatus 1300 may beconfigured as being separate from the CPU 100. For example, the bearermanagement apparatus 1300 may be configured as a chip connected to theCPU 100, and the functions thereof are realized under the control of theCPU.

As illustrated in FIG. 14, the UE 1400 may further include: acommunication module 110, an input unit 120, an audio processing unit130, a display 160, and a power supply 170. To be noted, the UE 1400does not necessarily include all parts as illustrated in FIG. 14. Inaddition, the UE 1400 may also include the parts not illustrated in FIG.14, please refer to the relevant art.

As illustrated in FIG. 14, the CPU 100 sometimes is called as acontroller or an operation widget, and it may include a microprocessoror other processor device and/or logic device. The CPU 100 receives aninput and controls the operations of respective parts of the UE 1400.

In which, the memory 140 for example may be one or more of a buffer, aflash memory, a floppy, a removable medium, a volatile memory, anonvolatile memory or any other appropriate device. It can storefailure-related information, and a program executing relatedinformation. In addition, the CPU 100 can execute the program stored inthe memory 140 to store or process information. The functions of otherparts are similar to those in the relevant art, and are omitted herein.The parts of the UE 1400 may be implemented by a dedicated hardware,firmware, software or combinations thereof, without deviating from thescope of the present disclosure

As can be seen from the above embodiment, by receiving an indicationmessage, sent by a base station, for changing a bearer type of a beareror releasing the bearer under dual connectivity, the UE configured withdual connectivity can seamlessly convert the bearer.

Embodiment 5

This embodiment of the present disclosure provides a bearer managementapparatus configured in a UE configured with dual connectivity. Thisembodiment of the present disclosure is corresponding to the bearermanagement method of Embodiment 2, and the same contents are omitted.

FIG. 15 is a schematic diagram of a structure of a bearer managementapparatus of Embodiment 5 of the present disclosure. As illustrated inFIG. 15, the bearer management apparatus 1500 includes a firstprocessing unit 1501 that is configured to release an SCG portioncorresponding to a split bearer; or, releases or deactivatescorresponding SCG when all bearers associated with an SCG are released.

In one embodiment, as illustrated in FIG. 15, the bearer managementapparatus may further include a triggering unit 1502 that is configuredto trigger an RRC connection reestablishment procedure; after thetriggering unit 1502 triggers the RRC connection reestablishmentprocedure, the first processing unit 1501 is configured to release theSCG portion corresponding to the split bearer and/or an SCG bearer.

In which, the triggering unit 1502 is configured to further release aconfiguration associated with the SCG Or, the first processing unit 1501is configured to further associate the SCG bearer with an MAC entitycorresponding to an MCG and release a configuration associated with theSCG.

In another embodiment, the first processing unit 1501 is configured todeactivate corresponding SCG when all bearers associated with the SCGare released, the corresponding SCG may not include cells of the SCGconfigured with a PUCCH and having a part of the function of the primarycell.

In another embodiment, as illustrated in FIG. 15, the bearer managementapparatus may further include a second processing unit 1503 that isconfigured to reestablish a PDCP entity and/or trigger a sending of aPDCP status report to the MCG when a bearer change from the split bearerto a traditional bearer or from the split bearer to an MCG beareroccurs.

As illustrated in FIG. 15, the bearer management apparatus may furtherinclude a transmission unit 1504 that is configured to perform a PDCPdata transmission or retransmission according to a received PDCP statusreport sent from a network side.

This embodiment of the present disclosure further provides a UEincluding the aforementioned bearer management apparatus 1500, pleaserefer to FIG. 14 for the structure of the UE.

As can be seen from the above embodiment, by receiving an indicationmessage, sent by a base station, for changing a bearer type of a beareror releasing the bearer under dual connectivity, the UE configured withdual connectivity can seamlessly convert the bearer.

Embodiment 6

This embodiment of the present disclosure provides a bearer managementapparatus configured in a base station connected to a UE configured withdual connectivity. This embodiment of the present disclosure iscorresponding to the bearer management method of Embodiment 3, and thesame contents are omitted.

FIG. 16 is a schematic diagram of a structure of a bearer managementapparatus of Embodiment 6 of the present disclosure. As illustrated inFIG. 16, a bearer management apparatus 1600 includes a detecting unit1601 and a sending unit 1602, the detecting unit 1601 is configured todetect that a radio connection fails at the UE configured with dualconnectivity; and the sending unit 1602 is configured to send to asecond base station a request for releasing an associated SCG bearer ora split bearer, so that the second base station releases a correspondingbearer.

FIG. 17 is a schematic diagram of another structure of a bearermanagement apparatus of Embodiment 6 of the present disclosure. Asillustrated in FIG. 17, the bearer management apparatus 1700 includes: areceiving unit 1701 and a releasing unit 1702, the receiving unit 1701is configured to receive a request, sent by a first base station, forreleasing an associated Secondary Cell Group (SCG) bearer or a splitbearer; and the releasing unit 1702 is configured to release acorresponding bearer according to the request for releasing.

This embodiment of the present disclosure further provides a basestation, including the bearer management apparatus 1600 or the bearermanagement apparatus 1700 described above.

FIG. 18 is a schematic diagram of a structure of a base station ofEmbodiment 6 of the present disclosure. As illustrated in FIG. 18, abase station 1800 may include a CPU 200 and a memory 210 coupled to theCPU 200, the memory 210 may store various data and an informationprocessing program, executes the program under the control of the CPU200 to receive various information sent from a UE, and sends requestinformation to the UE.

In one embodiment, the functions of the bearer management apparatus 1500or the bearer management apparatus 1700 may be integrated into the CPU200 may be configured to implement the bearer management method ofEmbodiment 3.

In another embodiment, the bearer management apparatus 1600 or thebearer management apparatus 1700 may be configured as being separatefrom the CPU 200. For example, the bearer management apparatus 1600 orthe bearer management apparatus 1700 may be configured as a chipconnected to the CPU 200, and the functions thereof are realized underthe control of the CPU.

In addition, as illustrated in FIG. 18, the base station 1800 mayfurther include a transceiver 220 and an antenna 230, the functions ofthese parts are similar to those in the relevant art and are omittedherein. To be noted, the base station 1800 does not necessarily includeall the parts as illustrated in FIG. 18. In addition, the base station1800 may also include the parts not illustrated in FIG. 18, please referto the relevant art.

As can be seen from the above embodiment, by releasing the SCG bearer orthe split bearer at the base station side, the UE configured with dualconnectivity can seamlessly convert the bearer.

Embodiment 7

This embodiment of the present disclosure provides a communicationsystem, and the contents the same as those in Embodiments 1 to 6 areomitted.

FIG. 19 is a schematic diagram of a structure of a communication systemof Embodiment 7 of the present disclosure. As illustrated in FIG. 19,the communication system 1900 includes a first base station 1901, asecond base station 1902, and a UE 1903 keeping dual connectivity withthe first base station 1901 and the second base station 1902.

In one embodiment, the UE 1903 is configured to receive an indicationmessage, sent by a base station, for changing a bearer type of a beareror releasing the bearer under dual connectivity; change the bearer typeof the bearer or release the bearer according to the indication message;and send a response message to the base station.

In which, the indication message includes first configurationinformation configured or reconfigured by the base station for a logicalchannel identity corresponding to the bearer, or second configurationinformation configured or reconfigured by the base station for a radiobearer identity corresponding to the bearer, or third configurationinformation configured or reconfigured by the base station for a PDCPentity corresponding to the bearer, or fourth configuration informationfor releasing the bearer under dual connectivity.

In another embodiment, after triggering the RRC connectionreestablishment procedure, the UE 1903 is configured to release an SCGportion corresponding to the split bearer and/or an SCG bearer.

In another embodiment, after all bearers associated with an SCG arereleased, the UE 1903 is configured to release or deactivatecorresponding SCG.

In another embodiment, the first base station 1901 is configured todetect that a radio connection fails at the UE 1903 configured with dualconnectivity, and send a request for releasing an associated SCG beareror a split bearer to the second base station 1902; and the second basestation 1902 is configured to receive from the first base station 1901,the request for releasing the associated SCG bearer or the split bearer,and release a corresponding bearer according to the request forreleasing.

This embodiment of the present disclosure further provides a computerreadable program, when being executed in a UE, the program enables acomputer to perform, in the UE, the bearer management method ofEmbodiment 1 or 2.

This embodiment of the present disclosure further provides a storagemedium which stores a computer readable program, the computer readableprogram enables a computer to perform, in a UE, the bearer managementmethod of Embodiment 1 or 2.

This embodiment of the present disclosure further provides a computerreadable program, when being executed in a base station, the programenables a computer to perform, in the base station, the bearermanagement method of Embodiment 3.

This embodiment of the present disclosure further provides a storagemedium which stores a computer readable program, the computer readableprogram enables a computer to perform, in a base station, the bearermanagement method of Embodiment 3.

The above devices and methods of the present disclosure may beimplemented by hardware, or by hardware in combination with software.The present disclosure relates to such a computer readable program thatwhen the program is executed by a logic unit, the logic unit is enabledto carry out the above devices or components as described above, or tocarry out the methods or steps as described above. The presentdisclosure also relates to a storage medium for storing the aboveprogram, such as a hard disk, a floppy disk, a CD, a DVD, and a flashmemory, etc.

One or more functional blocks and/or one or more combinations thereof inthe drawings may be implemented as a universal processor, a digitalsignal processor (DSP), an application-specific integrated circuit(ASIC), a field programmable gate array (FPGA) or other programmablelogic devices, discrete gate or transistor logic devices, discretehardware component or any appropriate combination thereof to perform thefunctions described in the present disclosure. And they may also beimplemented as a combination of computing equipment, such as acombination of a DSP and a microprocessor, multiple processors, one ormore microprocessors in communication combination with a DSP, or anyother such configuration.

The present disclosure is described above with reference to particularembodiments. However, it shall be understood by those skilled in the artthat those descriptions are illustrative only, and not intended to limitthe protection scope of the present disclosure. Various variants andmodifications may be made by those skilled in the art according to theprinciples of the present disclosure, and such variants andmodifications also fall within the scope of the present disclosure.

What is claimed is:
 1. A terminal capable of dual connectivity with abase station, the terminal comprising: a processor configured to performa process that changes a type of a bearer from Secondary Cell Group(SCG) bearer to Master Cell Group (MCG) bearer, releases the bearer, ordeactivates the bearer, and triggers transmission of a Packet DataConvergence Protocol (PDCP) status report when a PDCP entityreconfiguration is requested and an associated Radio Link Control (RLC)entity is released for a radio bearer according to the process; and atransmitter configured to transmit the PDCP status report.
 2. Theterminal according to claim 1, further comprising a receiver configuredto receive from the base station a control signal that indicates theprocess, wherein the processor performs the process according to thecontrol signal.
 3. The terminal according to claim 2, wherein, thecontrol signal includes a configuration information for a logicalchannel identity corresponding to the bearer.
 4. The terminal accordingto claim 2, wherein, the control signal includes alogicalChannelIdentity in an information element DRB-ToAddMod, and alogical channel identity corresponding to the logicalChannelIdentity ispresent.
 5. The terminal according to claim 2, wherein, the controlsignal includes a configuration information for a PDCP entitycorresponding to the bearer.
 6. The terminal according to claim 2,wherein, the control signal includes a pdcp-Config in an informationelement DRB-ToAddMod, and PDCP information corresponding to thepdcp-Config is present.
 7. The terminal according to claim 1, whereinthe processor triggers transmission of the PDCP status report accordingto the bearer type.
 8. The terminal according to claim 1, wherein theprocessor triggers transmission of the PDCP status report according tothe bearer type is changed from a first type to a second type.
 9. A basestation capable of dual connectivity with a terminal, the base stationcomprising: a transmitter configured to transmit to the terminal acontrol signal that indicates to change a type of a bearer fromSecondary Cell Group (SCG) bearer to Master Cell Group (MCG) bearer,release the bearer, or deactivate the bearer; and a receiver configuredto receive from the terminal a Packet Data Convergence Protocol (PDCP)status report that is transmitted by the terminal after the terminaltriggers transmission of the PDCP status report when a PDCP entityreconfiguration is requested and an associated Radio Link Control (RLC)entity is released for a radio bearer.
 10. The base station according toclaim 9, wherein, the control signal includes a configurationinformation for a logical channel identity corresponding to the bearer.11. The base station according to claim 9, wherein, the control signalincludes a logicalChannelIdentity in an information elementDRB-ToAddMod, and a logical channel identity corresponding to thelogicalChannelIdentity is present.
 12. The base station according toclaim 9, wherein, the control signal includes a configurationinformation for a PDCP entity corresponding to the bearer.
 13. The basestation according to claim 9, wherein, the control signal includes apdcp-Config in an information element DRB-ToAddMod, and PDCP informationcorresponding to the pdcp-Config is present.
 14. A wireless systemcomprising: a terminal configured to perform a process that changes atype of a bearer from Secondary Cell Group (SCG) bearer to Master CellGroup (MCG) bearer, releases the bearer, or deactivates the bearer,triggers transmission of a Packet Data Convergence Protocol (PDCP)status report when a PDCP entity reconfiguration is requested and anassociated RLC Radio Link Control (RLC) entity is released for a radiobearer according to the process, and transmits the PDCP status report;and a base station configured to receive from the terminal the PDCPstatus report.